


Back to the Future

by leavemeyourstardust



Category: Supergirl (TV 2015)
Genre: Crisis of Infinite Earths set up, F/F, F/M, Supergirl Season 4 Rewrite, karamel centric but does explore other ships, lots of angst & slow burn, lots of timey wimey stuff
Language: English
Status: In-Progress
Published: 2019-01-10
Updated: 2019-01-12
Packaged: 2019-10-07 20:01:53
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,020
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17372378
Author URL: https://archiveofourown.org/users/leavemeyourstardust/pseuds/leavemeyourstardust
Summary: A S4 Supergirl AU that sets up crisis on infinite earths.Once Reign and the Rogue Kryptonians are defeated, Kara and Alex are visited by a mysterious visitor from the future that claims all will be lost to Brainiac if Kara does not accompany her back to the future.





	1. Prologue A Knock on the Door

**Author's Note:**

> Hi I'm back !!! Sorry for the delay, I started art school and life kind of took over. I am planning on updating my old fics but I did a poll on twitter and my S4 AU sort of took the lead. I'll be updating this one every Thursday so keep an eye out for it! And if you have any thoughts & comments reach out to me on my twitter @benoistwoods. Although I'll be posting Chapter 1 a little sooner since the prologue is so short.

“ He did it,” Kara said with sigh watching the newscast of her friend Jimmy Olsen’s reveal as Guardian.

“How about Winn joining the Legion?” Alex asked from beside her on the couch tilting her head to the side as she spoke.

Kara let out a tight-lipped laugh. The subject of the legion would always make her feel a slight sense of unease. She quickly diverted away from the subject, not wanting Alex to catch on.

“Do you think he’ll make them new outfits?”

“Oh absolutely”

There was a moment of silence as Kara mulled over all the recent changes. J’onn had left Earth to do a pilgrimage to honour his father’s memory. Winn was gone. Mon-El was gone… 

She suppressed that aching feeling further, she couldn’t let it consume her like last time. She couldn’t mention him. Instead, she looked at her sister proudly. 

“ I’m so proud of you Director Danvers.”

Alex shook her head looking down. “ I’m proud of you. You gave up a chance to be with your mother, your people. I just…” she shifted in her seat uncomfortably, “ I’d hate to think it’s cause of me.” 

“ It’s not, “ Kara responded almost immediately, “ my place is right here in National City.” Her voice was adamant almost as though she was trying to convince herself of it. 

Her decision to stay had been out of duty, not preference. That’s what heroes did right? They sacrificed for others. Kara had to swallow the bitter pill of realizing that her role as Supergirl would always eclipse her needs as Kara Zor-El. It was naive to want for anything else. 

Alex seemed perturbed by Kara’s change in demeanour. She rested a hand on her sister’s shoulder about to speak when there was a loud urgent knock at the door. 

Kara and Alex turned. It was late evening but they weren’t expecting company. Kara used her X-ray vision to see an unfamiliar woman at the door. She rose as the knock occurred again. Kara walked over and opened the door. 

There stood a blond haired woman a few inches taller than Kara. Her hair was the same colour of warm sunshine blonde except it was streaked with bright pink. She wore a black bomber jacket paired with a bright yellow crop top, her jeans were frayed at the knees, and the doc martens she wore were moth-eaten. Kara’s eyes zeroed in on the necklace around her neck. Her necklace. Immediately her eyes darted downwards to see the familiar black and gold legion ring. 

“ My name is Laurel, I’m your daughter from the future…Mon-El sent me,” the woman explained in a soft slow voice, “ You are needed urgently there.”


	2. An Anomaly

**Summary for the Chapter:**

> The DEO group struggles to understand the implications that brought this mysterious visitor to Earth 2018.

**Notes for the Chapter:**

> Here is Chapter 1 officially. I apologize that this chapter is a bit exposition-y but somethings needed to be established. I promise Chapter 2 will be more action-packed and feature some sweet karamel. Comments & Kudos are always appreciated, if you want to reach out to me you can do so on my twitter @benoistwoods. Chapter 2 will be posted Thursday.

“ It’s impossible, “ Brainiac 5 said in defiance peering at the blonde haired woman in the DEO cell. “ She’s not supposed to exist.” 

“ And yet she does, “ Alex said, “ I ran the tests, she’s a match for Kara’s DNA. And she’s carrying residual tachyon energy, which according to the research Cisco shared means she’s a time traveller. I think she might be telling the truth. ”

Kara stayed quiet still watching the woman in the contained room with keen eyes. Alex peered over at her. 

“ What do you think? “

Kara looked at her.

“ I don’t know what to think. It’s not everyday you meet your supposed future daughter. At least...she’s cooperative.” 

“ So you don’t believe her?” Alex asked as Brainy nodded. 

“ Until we can contact the Legion in the future to verify her claims, Supergirl is being very wise in her decision to keep this stranger locked up.” 

“No comms available yet?” Alex asked her brow furrowed in worry.

“ Any message I send bounces back as though there’s no receiver to pick it up.” Brainiac rubbed his temples in frustration, “ I should get back to work. “ he stalked off. 

Kara too seemed ready to go. Alex chased after her. 

“Where are you going?”

“ To the fortress. Maybe I can find something that makes all of this make sense.” 

Alex sighed, but nodded. Kara was like a closed book again which made her feel even guiltier about the secret she was keeping. Once she saw the girl of steel soar above to the skies, she walked back to the room that held her supposed niece. Laurel was standing there with a knowing smile.

“ He told me you’d keep my secret.”

“ Who your dad?” Alex asked unsure how to feel.

Laurel shook her head. 

“No, my Uncle Winn. My dad and I...well it’s complicated. He was never the same after he lost Mom like that. I guess looking at me reminded him of her too much. Besides, he had a lot of responsibility to shoulder as the leader of the Legion and all of that. I was raised by you and Uncle Winn mostly.”

Alex cringed, raking a hand through her hair. 

“So I guess you lied about the fact that he sent you.”

Laurel nodded slowly taking a step forward. 

“He has no idea I’m here. This is a project between us Young Legionnaires. Nora’s here to save her dad and I’m here to save Mom.”

“And how do you intend to do that?”

“Nora’s got her own way. She’s struck some kind of deal with the devil,” Laurel rolled her eyes to indicate how disapproving she was of this Nora’s plans. “I’m taking Mom to the future to reunite her and Dad. She can’t die, if she’s not here when it comes.”

“When what comes?” Alex asked her eyebrows knitted together in costernation. 

“I can’t tell you that. I’m telling you enough so you can help me convince Mom to come with me. I know you’d do anything to keep her alive.”

Alex folded her arms defensively. On the one hand, this woman could be duping her. But there was overwhelming evidence to indicate she was Kara and Mon-El’s daughter. The necklace, the DNA compatibility, the legion ring she was wearing, and the fact that she spoke out of desperation. She’d known that desperation before, she’d had the same look on her face when Jeremiah had been found.

“ Okay I’ll bite, what’s the plan?” Alex asked as she typed in the combination to free Laurel from her containment chamber.

____

Kara soared through the skies on the way to the Fortress of Solitude. Her mind had been streaming since Laurel had arrived on her doorstep a few days ago. Here, she was thinking that she’d never know what it would be like to be a mother and just moments later this had happened. She couldn’t believe it. The Kryptonian had been desperately searching for answers since Laurel had been put in that containment chamber. However, she’d not met with her daughter face to face. She was terrified to learn who her father was. Her existence meant she had moved on from Mon-El and she couldn’t imagine a reality where she didn’t love him anymore. It was too much.

She touched down outside of the Fortress and walked in to see Kelex looming about. When he saw her he sharply came to meet her. 

“ Kara Zor-El you have a transmission from the year 2049, do you accept?”

Kara bit her lip, but nodded. 

Kelex sputtered and cast a beam where now a holographic Laurel stood. She wasn’t dressed in her punk rock attire, instead she wore a traditional Kryptonian dress, her hair was done up in a braided bun to hide the pink in it. She looked more like Kara than ever in this brand new get up. 

“ I dressed up like you. Isn’t that silly? But, I figured you wouldn’t want to see me face to face when I first came there. I’m probably not the daughter you imagined. And you probably don’t believe me. Which I get...you’ve suffered a lot of loss. I mean…  
I’ve only ever lost you. And it was like...losing a part of me I’ll never get back. You lost a planet. You lost your first love. But here’s the thing, you kept going. You saved Earth so many times. I mean, no wonder they’ve built monuments for you here.” Laurel’s eyes were glistening with tears she stubbornly wiped them away. 

“ I know you won’t believe me and if our calculations are correct the comms to a future time have been disengaged by Brainiac. So I did a bit of a time hack with this message. I left the Legion Ring in the fortress on a previous trip to act as a beacon so it would be activated at exactly the right time. And I have someone here you might believe,` give me a sec.”

Kara waited with bated breath as she watched a shorter middle aged man appear. His brown hair was greying, there were crinkles around his eyes, and a sharp scar along his jawline. There were changes in his demeanour, but Kara would have recognized him anywhere it was her best friend, Winslow Schott Jr. 

“ Hey Kara,” he began before clearing his throat. “ It’s been awhile hasn’t it? Maybe not for you...” he shook his head, “ irrelevant, I s’pose. Look, I know it’s probably really confusing for you right now having Laurel show up. It may seem almost impossible to you. But once upon a time, you showed me something impossible. So take a leap of faith, Kara. Come to the future. I can’t say much more than that, I’m just asking you to take a chance on us.”

The transmission cut out after that, Kara dropped to her knees as Kelex wavered near. 

So this was real after all. 

_____

Laurel stood at the blinking display staring up at it. Surrounded by all this primitive technology was almost comforting. Things were much simpler back here. Beside her Brainy kept shooting her furtive looks. 

“You got a problem, Blue boy?” she asked folding her arms.

“I don’t trust you.” Brainy said plainly, “and I think what we’re about to do is a fool’s errand. Mon-El would have sent word back.”

“He did,” Laurel replied adamantly, “ With me, your deranged grandfather has cut comms along the time stream after I arrived in your time to help.”

Brainy flushed, he hated having his relationship to Brainiac being brought up. 

“Something about this doesn’t feel right. I don’t understand how you exist. You didn’t exist when Imra and I returned to the future. And with Supergirl here...and M-”

Laurel walked right up to Brainy unflinchingly. Her stormy grey eyes zeroing in on him. “ So you know who my father is?”

“It’s obvious to anyone paying the least bit attention. I’ve known him for a long time and I hacked into Director Danvers’s findings on your genetic makeup. I just don’t understand the probability-”

“Somethings defy probability,” Laurel interrupted.

Brainy’s features softened as he looked down at the display in order to avoid Laurel’s intense gaze. 

“ Your father told me something similar once. This isn’t a feeling I’m familiar with but I do feel guilty about my actions. I know you’re here for Supergirl but I’d like to accompany you as well.”

“As do we,” said a deep voice from behind Laurel. She turned to see Martian Manhunter and her Aunt Alex walking towards them. Laurel’s eyes went wide, the Martian Manhunter hadn’t been seen in eons but his feats were of course legend. He morphed back into his human self. 

He offered his hand for Laurel to shake and she looked down almost as if it was part of a dream. 

“Nice to meet you, Laurel. Alex contacted me and asked me to return.”

“I thought we were keeping everything a secret,” Laurel said still in awe of the Martian as her eyes turned to Alex.

“ We are...from Kara.” Alex obliged, corking her gun. “But if things are as bad as you say they are. Then we’ll need back up.”

“Okay, okay I can get on board with Mr. J'onzz and you coming. But he can’t come.” Laurel turned to Brainy, “ your grandfather will try to use you against us.”

“ Yes but he is my family. If anyone’s going to put him down it’s gotta be me. It was wrong of me to send Mon-El and Winn there in my place. ”

There was silence following that. It seemed Brainy was fairly obstinate about going despite the risks.

“What about the AI plague?” J’onn asked as the voice of reason. 

Brainy seemed quiet for a moment, looking down at his feet, ashamed.

“ It doesn’t affect me. I’m not a purely AI construct. I’m both organic and otherwise. I was just a coward. I abandoned my friends, and my team when they needed me most. ”

It was Laurel that spoke up this time. Despite her brusque attitude towards him, she cleared her throat. 

“ I suppose we could use him, no one knows more about Brainiac’s internal hard drive better than Brainy.”

“It’s decided then. All we need now is Kara on board, “ Alex said as she looked around the small group. “And someone to watch over Earth while we’re away.”

“You’ve got both.” 

Kara arrived with James at her helm. Laurel stood up straighter when Kara entered the room almost as if there were strings attached to her spine. Kara purposely avoided her daughter’s gaze as her eyes fell on J’onn and Alex.

“ I found something in the Fortress. I’m still not sure if...if any of what she’s saying is true. But considering comms are not working and a whole generation of people are in danger. It’s worth investigating. Guardian will watch over National City while we’re away. The people seem to be rallying to his side. ”

“ I’ve also got Superman on speed dial in case something goes wrong,” James said folding his arms. He knew things hadn’t gone so well last time Kara had left Earth. But there was no imminent threat this time. He could handle it. 

“ Well I guess it’s decided then, we’re going back to the future,” Brainy said decisively scurrying off to make arrangements for their departures

_____

Preparations were made relatively fast. J’onn’s ship was repurposed into a time travelling machine thanks to the futuristic tachyon device Laurel had on her person. Alex delegated her directorial duties to Agent Cortez who seemed eager to step up. J’onn laid his father’s rites in his apartment ready to pick them up when he returned. Kara meanwhile, gave her notice at CatCo. All this back and forth with her job made her realize that it wasn’t the place for her. Where did she belong? That answer was still ambiguous to her. All she knew was if she didn’t go to the future, there would be a nagging voice in her head asking, what if?

She stood on the tarmac where the ship was being loaded with some essentials. Brainy had taken down the earthly disguise mechanism making more room in the lower hull. This would make sure the four of them fit comfortably. It wasn’t that long ago she had sat in that ship with Mon-El and felt at complete peace with herself. Now all she felt was anxiety. 

What was happening in the future? Were Winn and Mon-El alright? 

Moreover, could Laurel be trusted?

Her eyes moved to rest on the other blonde standing a few feet away, she was grasping the necklace and looking down at it, a single tear burgeoning in her eye. Kara rubbed her lips together. She had to face Laurel sooner or later. Taking a deep breath, she took a few steps toward her.

“ Hey, are you okay?” Kara asked placing a hand on Laurel’s shoulder. She felt a sudden rush of protectiveness wash over her.

Laurel nodded slowly.

“ Yeah, just a bit overwhelmed. I can’t believe I accomplished my mission. Or well, I’m on my way to accomplish my mission.” she looked up and Kara was nearly dazzled by how much her eyes looked like the charcoal grey expanse of swirling galaxies. So much like Mon-El’s. She couldn’t be? Could she? Kara brushed that thought away as quickly as it came. Instead, her gaze dropped down to the necklace in Laurel’s hand.

“Where did you get the necklace?”

“Mon-El gave it to me. It belonged to Grandma, and then you. He thought I was the rightful owner.”

“Is he..?”

Laurel seemed to know what Kara meant, even though her question was more than a little vague.

“He and Imra went their separate ways after returning. He devoted his life to Legion, training us, and making sure everyone was taken care of. Never had...never had children of his own. Imra married again, his name is Garth. He was Mon-El’s second in command.”

“Why did you go to the future from 2049?”

Comprehension dawned on Laurel’s features. 

“ You saw the transmission. Uncle Winn was right !” she fist pumped the air excitably, before regaining her composure. “ Sorry, we weren’t sure if it would ever reach you. I’m glad it did. But like he told you, I can’t say much. Me coming here was dangerous enough. Mon-El warned me to be extra careful in regards to the timeline. But if you don’t go to the future now, dire consequences will follow.”

Kara knew from Barry that time was a fragile thing. Everything in her gut however was telling her to go on this journey just like everything in her gut had told her to travel back to save Mon-El, her mother, and Sam just a few days ago. Her gut had never proved her wrong.

“ I’m trusting you, for now” Kara finally said, “although I’ll be honest I’m really weirded out.”

Laurel put up her hands playfully. “ I would be too, but I won’t let you down, I promise.”

Alex came out from the ship jogging over to the two blondes. 

“ You two ready to go? Brainy thinks if we make headway now we’ll beat the meteor shower.”

Laurel nodded, giving Kara a tentative smile, before she boarded the ship. Kara and Alex looked at each before exchanging a hug. 

“ You think the future’s ready for the Danvers sisters?” Kara asked trying to lighten the mood.

“ Guess we’ll find out.”


End file.
